Preparation

• In a small bowl, mix 4 tsp. salt and 1 tsp. pepper with the sugar and cumin. Put the meat on a heavy-duty rimmed baking sheet, brush 1 Tbs. of the oil on the brisket, then rub the spices onto both sides. Cover with plastic wrap, and refrigerate for at least 6 and up to 24 hours.
• Position a rack in the top of the oven, and heat the broiler. In a large bowl, toss the onions with 1 Tbs. of the oil and 1 tsp. salt. Put the brisket on a broiler pan, and scatter the onions all around. Broil until the brisket and onions are browned, about 5 minutes. Remove the onions from the pan, flip the meat over, and broil the other side until browned, about 2 minutes more. (Broilers can vary in strength, so stay close to the oven, and check on the browning often.)
• Position a rack in the center of the oven, and heat the oven to 350°F. Heat a Dutch oven (7-1/4 quarts or larger) over medium heat. Add the remaining 2 Tbs. oil, the celery, and parsnips, and cook, stirring, until the parsnips soften and brown in places, about 9 minutes. Add the wine, increase the heat to high, and cook, stirring occasionally, until the liquid almost completely evaporates, about 6 minutes. Stir in the broth, tomato paste, honey, bay leaves, and star anise, and bring to a boil. Add the brisket, onions, and any accumulated juices to the pot. Cover and transfer to the oven.
• Roast, turning the brisket every 30 minutes, until the beef is tender, about 3 hours total. Transfer the beef to a carving board, tent with foil, and let rest for 10 minutes. Meanwhile, skim the fat from the cooking liquid. Transfer the liquid to a gravy boat, stir in the vinegar, and season to taste with salt and pepper.
• To serve, thinly slice the brisket, arrange on a platter with the vegetables, and top with the sauce. Serve, passing the remaining sauce at the table.